4 replies to this topic

[microgirl]

Anyone know how concentrated I can make TBE buffer - I've seen up to a 10x recipe, but I'd like to make 50x - just not sure that all that boric acid will go into solution.

[tfitzwater]

Precipitation of TBE frequently occurs, especially when a 10x stock is prepared. (Molecular Cloning, Sambrook et al)  5x stocks are more stable.   Autoclaving will retard this reaction.  Alternatively, filtration shortly after preparation through a 0.2-0.45 µm cellulose acetate or cellulose nitrate membrane will reportedly allow a 20x stock to be prepared. (Krainer, Adrian R.; Mayeda, Akila.  1991.  Long-term Storage of Concentrated Tris-borate-EDTA Electrophoresis Buffers without Precipitation.  Benchmark, Biotechniques, Vol.10, No.2, p.182 )  30x stocks prepared by this method are stable for 2 weeks.  Filtration suggests that nucleation of salt crystals by dust particles or other microscopic insoluble material is responsible for the precipitation problem.  If turbidity develops in filtered buffer stocks, autoclaving for 5 minutes at 110°C will remove cloudiness.  10x stocks that have massive amounts of crystallization can still be used to prepare 1x TBE without affecting the resulting voltage, watts or amps.

[Adrian K]

IMHO, I will not prepare anything more than 5x for TBE buffer. I used to prepare a lot of 5x buffer but in the end all was crystallized. Since I use only 0.5x buffer, I only prepare 1x and this last me for quite long as well.

Just curious: why you want to do up to 50x ? Do you think after dilutions into 1x or 0.5x , the pH and buffer strength will be less likely to be affected (unless yours is neutral water)?

For 1 Liters of 10x TBE, you need: 108g Tris base, 55g Boric acid, 40mls 0.5M EDTA (pH 8.0)
(I read somewhere in this forum says that prepare 1M EDTA is impossible)

Since you want 50X TBE, I am skeptic if you can really dissolve 540g tris base, 275g Boric Acid, 200ml 0.5M EDTA into a 1 liter solution. Adding 815g powder of tris base and boric acid takes almost a full bottle, and adding 200ml EDTA I'm skeptic about how will it dissolve the tris base and boric acid. which the salt amount is more than the solution. Furthermore, I think you hardly top up dH20 into your bottle.

So,in my humble opinion, to prepare 50x TBE is impossible. If you can do it please let me know how.

Anyway, I was thinking if I prepare 1 liter 50x TBE and I got 100 liter to use... not a bad idea..

[Trof]

We prepare several litres of 10x TBE and then autoclave it and we never had problems with crystalization.

[BryanC]

Can't speak to the logistics of making it on the bench yourself, but a colleague used to use tablets he purchased somewhere that would dissolve to prepare 50x TBE.  He seemed to like them, but I can't remember what vendor they were from.